Electrical non-conductor



(No Model.)

C. T. LEE & G. N. WAITE.

ELECTRICAL NON-CONDUCTOR.

No. 386,925. Patented July 31, 1888.

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UNITED STATES PATENT OFFICE.

CHARLES TENNANT LEE, OF BOSTON, AND CHARLES N. WAITE, OE MED- FORD,ASSIGNORS OF ONE-HALF TO THE GOULD & WATSON COMPANY,

OF BOSTON, MASSACHUSETTS.

ELECTRICAL NON-CONDUCTOR.

SPECIFICATION forming part of Letters Patent No. 386,925, dated July 81,1883.

(No model.)

To all whom it may concern.-

Be it known that we, CHARLES TENNANT LEE,ofBoston,county ofSuffolk,andCHARLES N. \VAITE, of Medford, county of Middlesex, State ofMassachusetts, have invented certain new and useful Improvements inElectrical Non Conductors, of which the following is a specification,reference being had to the drawing accompanying and forming aparthereof, in which is shown a sectional view of a piece of ournon-conductor enlarged.

Non conductors 'for electrical purposes which can be produced in thinflexible sheets of large size are, so far as known to us, expensive anddifficult to obtain.

The chief object of our invention is the production at slight cost of anon-conductor having a high degree of resistance, and which, whendesired, may be produced in thin fiexible sheets of any required size;and it consists in a sheet composed of a layer or layers of fabriccoated or filled with an insulating materialsueh as mica in a comminntedstatewhich is attached thereto by an adhesive substance, such as glue,British gum. or the like.

In the drawing, a to represent the threads of the fabric, and b the massof insulating material, the whole being very much enlarged for thepurposes of illustration. We prefer to use a coarsely woven cotton clothof fine thread, known as cheese cloth, when thin sheets of thenon-conductor are desired; but, as will be obvious,when thinness of thesheet is not essential, a thicker and more closelywoven fabric may beused.

The mica may be applied in various ways to the fabric; but we prefer toapply it by saturating the fabric in glue size, then running the sizedfabric th rough the comminuted mica, so as to thoroughly cover it withthe same, and then passing the fabric through a pail-of rolls such asare commonly in use in a friction starch-mangle, and thus forcing themica scalesinto and through the sized fabric. When the fabricis dried, asheet of material is obtained having the non-conducting qualities of acontinuous unbroken layer or sheet of mica.

As will be obvious, if a non-conductoris desired which shall beimpervious to moisture, this result may be obtained by coating thesheets with shellac or other resinous varnish.

\Vhat we claim is A non -conductor consisting of a sheet or layer oftextile fabric saturated or filled and covered with a compound composedof com lninuted mica and an adhesive material, as glue, substantially asset forth.

CHARLES TENNANT LEE. CHARLES N. WAITE. Witnesses:

WM. A. MAcLEoD, M. A. TaoMPsoN.

